Muffler



T. T. TVEDT.

MUFFLER.

APPLICATION FILED sEPTI I2. I917.

Patented ma 6, 1920.

UNITED STATLLWENT OFFICE.

THOMAS '1. TVEDT, OF BROOKLYN, NEW YORK."

MUFFLER.

Specification bf Letters Patent. t t J l fl 1920 TApplicationfiled September 12 1917. Serial No. 190,955.

To all whom it may concern: a

Be it known that I, THOMAS T. Tvnn'r, a citizen of the United States', residing at Brooklyn, New York, have invented certain new and useful Improvements in Mufflers, of which the following a clear, full, and exact description. e I V I This invention relates to sound mufiling or silencing devices, and particularly to mufflers adapted to silence the exhaust from internal combustion engines.

A general object of the invention is to provide a muffler with which a maximum of silencing effect may be produced w th a minimum of back pressure upon the engine.

More particularly the invention aims to provide a muffler which maybe ad usted to the performanceof any particular engine of the type for which t 18 a which, nevertheless, is simple and durable in construction and inexpensive to manufacture.

Another object of the invention is to improve mufflers of the type disclosed in m co-pending application, Serial No. 152,928, filed 'March 6, 191?, and particularly to facilitate the expansion of the gases into the successive chambers of a muffler of this type, and also to accelerate the travel of the gases through the muffler, thus further improving mufflers of this type with respect to the engine.

Other objects and important features of the invention will appear from the'following description and claims when considered in connection with the accompanying drawings, in WlliClle 1 Figure 1 is a longitudinal sect on through a muffler-embodying the present invention, on the line 1-1 of Fig. 2; j

Y Fig. 2 is a transverse section illustrating the construction of the by-pass and its closure in the transverse baffle plate;

Fig. 3 is an end view of the outlet end of the bafile'casing;

Fig. 4: is an end view the baffle casing; and

Fig. 5 is a plan detail of the deflector by back pressure action upon the of the inlet end of which whirling motion is imparted to the exhaustgases. v

The illustrated mufller, which is of the general type of that shown in my co-pending application, Serial No. 152,928 hereinabo'veidentified, comprises a casing formed designed and j of end plates 2 and/1 provided ,i .n'their opposed faces with annular seats 6 and 8 for the cylindrical shell 10 which forms the cylindrical outer wall of the casing, these seats being somewhat beveled to insure a substantially gas-tight joint when the plates 2 and 4; are crowded toward each other and into engagement with the endsof the shell 10 by means of the connecting bolts 12,

which preferably'have a head 14 at one end and a nut 16 threaded upon the other end. Two of the bolts 12 are arranged to con: stitute guides for-the transverse baffle plate 18, having perforated ears 20 which receive said'guide's. The plate 18 forms the end wall ,of a cylindrical baffle, the illustrated cylinder being formed by a cylindrical shell ,21 seated at one end upon a flange 22 upon the plate Y18, and at its other end upon a flange 24% upon a ring 26 having ears 28 guided upon the rods 12, upon which the plate '18 is also guided.

The exhaust gases to be muffled are introduced into the muffler through an opening 30 in the wall 2 of the casing and this opening is surrounded by a cylindrical baffle comprising a cylindrical shell 32 seated upona flange 3 1 upon the inner side of said plate 2, said cylinder 32 preferably extending within the cylinder 21, which is preferably adjustable toward and away from the open end of the cylinder 32 in the manner hereinafter to be described.

The chamber within the cylinder 32 con stitutes the first expansion chamber of the muffler, and in order to facilitate the expansion of the. gases within this chamber and also within the succeeding chambers, means is preferably provided for imparting a whirling motion to the gases about the the opening 30, through which the exhaust .gases enter the casing, upon a diameter of said opening, the plate being cut back, as

shown, away from said opening so as not to interfere with the free entrance of the gases into the chamber in the cylinder 32; At its end remote from the opening 30, the plate .36 is split as shown at 38, and the two parts of the plate are so bent, with respect to the axis, of the cylinder, as shown in Fig. 1 of the drawings, that they tend to impart a common axis of thevarious cylinders. The.

whirling motion to the gases passing over said plate, this whirling motion being about the axis of the cylinder. Such wh1rling motion tends of course to effect a centrifugal movement of the gases and thus to facilitate their expansion toward the wall of the chamber, and accordingly their rapid expansion into the chamber in the succeeding cylinder 21, thereby also accelerating their travel through the mufller.

As in themui'fler shown in my co-pending application hereinabove identified, the cylindrical battles are preferably arranged for telescopic adjustment to vary the relative capacities of the succeeding expansion chambers, and in the illustrated construction means is provided for moving the cylinder 21 upon its guides 12 to carry its end wall 18 toward and away from the open end of the cylinder 32. The illustrated means comprises a rod 39 threaded through the plate 18 and having a bearing in the end plate 4 of: the mufller casing, this rod preferably having a squared end by which it may be engaged for turning, and having a set nut 40 by which it may be locked in adjusted position.

The illustrated mullier, like that in my co-pending application above identified, is preferably also provided with a by-pass through which, if desired, a selected proportion of the exhaust gases may be directly conducted from the first expansion chamber to the last without passing the cylindrical baflle 21. This by-pass comprises a series of ports 41 in the plate 18 within the cylinder 21', normally closed by a shutter 42 having a corresponding series of openings adapted to register with the ports ell when the shutter is turned part way about its axis, this shutter being mounted upon a shaft 44 having a bearing in the plate 18 and a sliding bearing in the plate 4. A handle 16 upon the shaft 44 may be swung from one position to the other, as shown in Fig. 3 of the drawings, to effect the opening and closing oi. the ports 41.

hen the mulller is used for muflling the exhausts of marine engines, means is preferably provided for cooling the mufiler, the illustrated means comprising a spray pipe 18 connected with the water inlet opening 50, this spray pipe being located between the cylinder 32 and the cylindrical wall 10 of the mufller casing in such position that it sprays water over the outside of the cyl inder 32. A branch 52 from the pipe 48 is preferably arranged to conduct a portion of the entering water through the wall of the cylinder 32 .into the inside of the cylinder, in such position that it discharges a part of the water upon the plate 36 by which the whirling motion is imparted to the en tering gases. This water not only tends to cool the muffler proper but also to cool the gases, thus further helping to reduce the back pressure upon the engine. Both the water and the gases are conducted out of the muffler through the opening 54 in the end wall 4 of the mutller casing.

What I claim as new is 1. In a mull'ler, a cylindrical expansion chamber open at one end, means for conducting the exhaust gases into the other end of said chamber, stationary means for imparting a whirling motion to said gases as they enter said chamber, a second expansion chamber into which said first chamber discharges from its open end, and means accessible from outside of the mufller for effecting a variation in the relative capacities of said chambers.

2. In a muffler, a cylindrical expansion chamber open at one end, means for conducting the exhaust gases into the other end of said chamber, means for imparting a whirling motion to said gases as they enter said chamber, a casing providing an expansion chamber outside said cylindrical chamber, a baffle plate in said casing and means accessible from the outside of the muffler for ad.- justing said baflle plate toward and away from the open end of said chamber.

3. In a mufller, a cylindrical balfle open at one end and providing an expansion chamber within, means for introducing exhaust gases into the other end, means for imparting a whirling motion to the gases as they enter the expansion chamber within said battle, a casing outside said batlle providing a second expansion chamber, and means for conducting cooling water over the outside of said baxllle and for introducing cooling water into the chamber within said baflle.

1. A mulller comprising a series of communicating expansion chambers, means for varying the relative capacities of said chambers, means for conducting the exhaust gases to the initial expansion chamber, and means for conducting at will a "fractional portion of the gases directly from the initial chamber to the last of said series of expansion chambers.

5. A mufller comprising overlapping concentric cylinders of different diameters having end walls at their remote ends, said cylinders being arranged to telescope to vary the relative capacity of the successive expansion chambers, means for conducting the gases from the exhaust into said cylinders, and a valve controlled port in the end wall of one of the cylinders arranged to permit the passage of a fractional portion of the gases directly through said cylinders.

6. A muffler comprising a casing having therein a series of ballles forming in said casing a series of communicating expansion chambers, said baflles being relatively adjustable to vary the relative capacities of the expansion chambers, and a valve controlled by-pass for conducting a portion of the exhaust gases past said baffles.

I 7. A mufiier comprising overlapping concentric cylinders of different diameters having end walls at their remote ends, said cylinders being arranged to telescope to vary the relative capacity of the successive expansion chambers, means for conducting the gases from the exhaust into said cylinders, and a valve controlled port in the end wall of one of the cylinders arranged to permit the passage of a portion of the gases directly through said cylinders.

8. In a muffler the combination with a muffler .casing, of concentric cylindrical bafiiers within said casing providing successive expansion chambers for the exhaust gases, means for introducing the exhaust gases into the chamber in the innermost battle and stationary means for imparting a whirling motion to the gases on entering said innermost bafiie to throw said gases toward the walls of said chamber.

Signed at New Yorl ,'N. Y., this 31st day of August, 1917. v

. THOMAS T. TVEDT. 

